One of the more important properties of a xerographic hot roll fuser is its ability to resist the adhesion of toner/paper to the hot surface of the roll, as the paper exits the fusig nip.
Silicone elastomers are well known in the xerographic art as suitable materials for use as fuser rolls. It is also known that these elastomers may be compounded with filler materials, such as oxides of silicon, iron and aluminum, in order to provide improved physical strength and thermal conductivity. These fillers, while generally desirable, are also known to inhibit release of the paper/toner from the hot elastomer, as the paper exits the fusing nip.
Two general types of such hot roll fusers are wet-release and dry-release fusers.
Dry release fusers have the advantage that fuser oil is not required as a consumable product within the copier device, and the resulting copy paper does not appear to have an oil-like coating. However, the dry-release fuser technology may result in greater difficulty in getting the molten toner to release from the hot elastomer surface as the copy sheet exits the fusing nip.
U.S. Pat. No. 3,848,305 is a particularly good example of a way in which the dry-release fuser technology has been advanced by a manufacturing technique which subjects the roll's silicone elastomer to heat and vacuum curing, in order to remove the cyclic siloxanes known to cause failure of the paper and its toner to release from the roll's surface.
U.S. Pat. No. 4,188,423 is also of interest. In this patent, it is suggested that the hot roll's silicone rubber layer be subjected to a solvent in order to remove siloxanes, polysiloxanes and other impurities from the rubber. More specifically, this patent states that the solvent must be of the type which does not react with, degrade or dissolve the silicone rubber.
Both of these prior art patents are incorporated herein by reference for the purpose of illustrating the state of the art and the background of the present invention.